Our research program is directed at measuring protein synthesis rates in a rat-tumor model. We use 15N as the tracer to measure the rate of protein synthesis in rat heart, liver, kidney, muscle, lung, and tumor. The objectives of the project are (1) to complete the development of this rat tumor model; (2) to investigate the effects of calorie and nitrogen deficiencies on the host-tumor interaction; (3) to see if by dietary manipulation the effects of 5-Fluorouracil on the tumor and host tissues can be modified and (4) to use this information to maximize the theraputic effectiveness of 5-Fluorouracil. BIBLIOGRAPHIC REFERENCES: "Tumor Caused Changes in Host Protein Synthesis Under Different Dietary Situations" Stein, T.P., Oram- Smith, J.C., Leskiw, M.J., Wallace, H.W., Miller, E.E. Cancer Research 36:3936-3940, 1976.